@media (min-width:300px) and (max-width: 400px){
	body {
		margin: 0px;
	}
    .left {
		display: none;
	}
	#app {
		display: block;
	}
}
@media (min-width:400px){
	body {
		margin: 0px;
	}
    .left {
    	display: block;
    	width: 180px
    }
	#app {
		display: flex;
	}
}